Solar Research Paves Way for Energy-Harvesting Glass

A UK-based company is developing solar-cell technology that could help advance the market for integrating solar energy-harvesting glass into commercial buildings.

Oxford Photovoltaics (PV) -- co-founded by Oxford University physicist Henry Snaith -- is using a material called perovskite to develop thin-film solar cells that can be printed directly onto glass to be used as semi-transparent, solar-energy harvesting material in large buildings. This potentially new market for solar cells -- the so-called building integrated photovoltaic, or BIP, market -- is in its nascent stages, but is poised to become a key commercial use of solar energy in the future.

“Once integrated in a glass-clad building, the technology is capable of powering much of the building’s lighting and IT infrastructure using solar power,” Ed Crossland, a senior development scientist at Oxford Photovoltaics, told Design News.

UK-based company Oxford Photovoltaics is developing thin-film solar technology that can be printed directly onto glass to enable large-scale use in commercial buildings. (Source: Oxford Photovoltaics)

Using perovskite -- a calcium titanium oxide mineral composed of calcium titanate -- in the production of these cells has several advantages over other silicon-based thin-film cells, including higher efficiency and less cost in cell production. “The remarkable fact is that despite being so easy to manufacture, the solar-harvesting properties of perovskite films compare very favorably to other PV technologies, which require more expensive and energy-intensive manufacture,” Crossland told us. “The perovskite is a very strong absorber of light in the solar spectrum. High-charge mobility means that electronic charges can move quickly to the cell terminals, and the material tends to minimize the energy loss inside the cell. Put simply, the perovskite is a very strong absorber of sunlight, and electronic charges generated inside the cell are very efficiently collected at the cell terminals to give useful power out.”

The current material sets and design of Oxford PV’s cells have already taken power conversion efficiencies to above 16%, which Crossland said is “significantly ahead” of amorphous silicon, which has a 12% efficiency. This percentage also has perovskite-based cells closing in on other thin-film technologies like Cadmium telluride, or CDTe, which is currently at 17% efficiency, and Copper indium gallium (di)selenide, or CIGS, which has 20% efficiency. “With further material development and design optimization, single-layer perovskite solar cells will deliver efficiencies above 20%,” Crossland said.

To produce the cells, the company applies a wet coating of the perovskite-based material onto architectural glass, and then seals it with another sheet of glass to protect it. Oxford PV is licensing this process and technology to third parties to produce the cells and plans to demonstrate samples from its first licensees in about two years. Following that, volume production of the cells should begin in 2017, Crossland told us.

The company initially is targeting the commercial sector with its technology, where the potential for use of thin-film solar cells is greatest.

"With designers using more and more glass in buildings, this could be a great technology, as long as the price is good."

Technochip, using more glasses for buildings are not ecco friendly because glasses can despite more heat. Inorder to maintain the normal room temperature, AC has to be work more. So instead of that, if we are able to stick these films over wall, it's becomes more economical.

"Oxford University physicist Henry Snaith -- is using a material called perovskite to develop thin-film solar cells that can be printed directly onto glass to be used as semi-transparent, solar-energy harvesting material in large buildings"

Elizabeth, I think rather than pasting these films over glass, it's better to be pasted over the outside walls of big buildings. so large areas can be covered and it's a cost effective solution too.

Nice share Liz. It's really astonishing to see the developments being done in Solar Energy as the already present technology is very costly for the consumers.The only thing that worries me about these cells is the stability. Even if they are cheaper than the already present PVs, will they be able to remain stable for a longer period of time with minimum degradation?

Elizabeth, this is a great way to harvest energy. If the cost of the process is not unfavorable, then it could indeed be a revolution. This type of process could be used to retrofit existing buildings fairly easily, as well as being applied to new construction. With more efficient lighting and computing equipment I could see buildings using this energy primarily. With good storage technology, it would easily pay for itself.

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